Hunt for under-priced used books that you can sell online. Download an app that reads ISBN numbers so you can scan the barcodes on books. This will pull up the book’s current price on Amazon so you can see if it’s worth trying to resell it. Then, visit used book stores, thrift stores, and garage sales to look for high value books. Post the books for sale online using sites like Amazon or Ebay.
Tutor students. Many families prefer the flexibility of using an online tutor. Depending on your background, you could be simply helping a child with homework or providing college-level support. You need to have your own computer and high speed internet. Experience required differs among companies. Some require “strong experience,” while others require a specific educational background. However, most companies do require a college degree.
You could try advertising more, for example, by putting up signs around the neighborhood, posting about it on social media, or having people you know spread the word. You could also try doing it in a different neighborhood that might have friendlier people, or do it in a time and place where there's likely to be a lot of people walking around the area (e.g., near a church before the end of a mass).
These ways of making extra money cover a wide range in terms of compensation and prestige. Check out the options to see what could work for you, keeping tabs on a projected per-hour rate so you can see what would be worth your time. The list is loosely arranged by 1. jobs requiring more skill or expertise, 2. gigs needing less and 3. things you can sell. And if you think of any good options I missed, please let me know in the comments.
I have seen Amazon affiliate sites that were so poorly done they made nothing or maybe were lucky to earn $20 to $30 per month. And I have seen some that make well over $1000 per month. But if you speak with experienced Amazon affiliates they will tell you that the average is probably somewhere around $300 to $500 month, per site, which is why most of the pros have ten or more sites.
Find a profitable niche. Starting with your interests, write down as many niche ideas as you can. Think about topics people might search online. Ideas include passions (like surfing or body building), fears (like spiders or speaking in front of crowds) and problems (like getting out of debt). Do keyword research to see it others are interested in the topic. Find out if a domain name is available that matches the keyword 100 percent. 
Take it seriously. Yes, you’re applying for an online job. Yes, you can do the work in your underwear, but that doesn’t mean it’s not a “real job”. You must treat it as such or they aren’t going to treat you as a serious candidate. You aren’t the only one who wants to work in their underwear. In fact, the competition online is likely higher than it is in your local area.
However, one day I had a reader offer to write a book review for me. I knew the reader so I was confident the review would be OK to publish. As with all my reviews, it had an affiliate link to Amazon in it. I was a little skeptical about whether the review would convert. I thought my readers might not respond as well to a stranger’s review of the book. I was wrong.
I have started looking at affiliate networks and finding products to promote that way. Also going to try to utilize a Youtube channel with promotion, as well as some paid advertising. It all works with the right amount of patience. I do have an Amazon Affiliate account that I can link too, but diversifing and learning to branch out is key. Truthfully I do not think the Amazon associate program is all that newbie friendly.
My 10-year-old son brought home a book from our park’s free library box. It was a biology textbook – teachers edition. He said it looked interesting and hey, it was free (having no idea you could sell it). I scanned it in my Amazon seller app and realized it was worth around $150. He was so excited. We listed it for sale for $130 and it sold! Going to tell him, he just made $130!
Note: I think the line where readers will push back probably will vary from blog to blog depending upon their readership. For example here on ProBlogger I get a little more negative feedback from readers on affiliate promotions. I suspect ProBlogger readers are a little more tuned into the issue and suspicious of some of the affiliate marketing that goes on around the web.
“Great list! I especially like the tutoring stuff. I’m good at Math that’s why I tutored once for my godparent’s 8th grader. I had fun with the her and her mum cooks the most delicious brownies. I don’t think I can donate a plasma or be a human guinea pig. But maybe you should add herb and vegetable planting. This job doesn’t require too many technicalities and is so far the easiest thing to do. There’s a method called square foot gardening for those who don’t have big spaces. It’s so simple to do and gardening in small boxes requires small maintenance. There is plenty of information on the web about how to do so. Once you get growing you can even sell your fresh produce to your neighbours at a cheaper price, and earn some fast money in the process . P.S. I also would want to partake in an online survey. Some people recommended Cash Crate but I’m also curious about what happened to you?
One great way to get ideas for related products to promote is to look at the stats/reports that Amazon gives you to see which products readers are buying. After a while you’ll start to notice that they’re not only buying the products you directly promote but other products as well. Some will be completely irrelevant to your niche – but many times trends will emerge that could signal other products that it might be worth promoting.